1. Field of the Invention
The present invention relates to a display terminal device connectable to an external display device, and a method for the display terminal device.
2. Description of the Related Art
In general, when a projector (external display device) is connected to a display terminal device such as a portable terminal device including a touch panel on a display screen at the time of presentation in a meeting or the like, and contents displayed on the terminal screen are projected onto a screen, all that is projected are the contents displayed on the terminal screen. Therefore, it is difficult to let participants viewing the screen in the presentation know a relation between a touch operation and the displayed contents, or in other words, a relation between the type of a touch operation performed on the terminal screen and how the displayed contents are changed thereby.
To address this problem, a method may be applied in which the status of a touch operation on a terminal screen is captured by a camera and the captured image is projected onto a screen for demonstration of the touch operation. However, in this method, part of the display screen is often hidden under a finger or palm at the time of a touch operation, which makes projected contents extremely difficult to view.
Conventionally, a technology has been proposed which supports demonstration of a touch operation. In this technology, when a touch operation is performed on a display terminal side with a external display device being connected to the display terminal device, a mark indicating the touched point is displayed on the terminal screen and a corresponding point on the external display device (Japanese Patent Application Laid-Open (Kokai) Publication No. 2007-310903)